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SMARTER STREAMING loading splits video streaming into two layers – a base layer, which contains a rough representation of the video, and an enhanced layer, which completes the image quality including fine detailing. This allows

users to download the enhanced layer onto their devices in a location where the wireless signal is strong and stream only the base layer at the time of viewing. Professor Panwar estimates that the technique could remove as much as 75 percent of the streaming content from wireless networks and reduce data usage for consumers.

detected: a human cancer marker protein called Thyroglobulin, with a mass of just 1 attogram, and the bovine form of a common plasma protein, serum albumin, with a far smaller mass of 0.11 attogram. “An attogram is a millionth of a millionth of a millionth of a gram,” said Arnold, “and we believe that our new limit of detection may be smaller than 0.01 attogram.” This latest milestone builds on a technique pioneered by Arnold and collaborators from NYU Polytechnic School of Engineering and Fordham University. In 2012, the researchers set the first sizing record by treating a novel biosensor with plasmonic gold nano-receptors, enhancing the electric field of the sensor and allowing even the smallest shifts in resonant frequency to be detected. Their plan was to design a medical diagnostic device capable of identifying a single virus particle in a point-of-care setting, without the use of special assay preparations. At the time, the notion of detecting a single protein—phenomenally smaller than a virus— was set forth as the ultimate goal.  The method, named “whispering gallery-mode biosensing” uses a laser which emits light through a glass fiber to a detector. If a microphone is

placed against the fiber, specific wavelengths of light detour into the gold nanosphere. The light trapped in the sample decreases the amount of light received by the detector. Once a cancer marker is introduced into the sphere, the resonant frequency shifts markedly. This allows a researcher to conclude, from the shift in frequency what marker is being detected by the biosensor. Unlike traditional methods, which attach fluorescent molecules, also known as labels, to antigens for detection, Arnold’s method allows antigen detection without labels. The implications of single protein detection are significant and may lay the foundation for improved medical therapeutics. Professor Arnold and his colleagues believe the ability to follow a marker in real time using the biosensing technique will yield groundbreaking understanding of how proteins attach to antibodies. Professor Arnold, in a partnership with Professor Xudong Fan (University of Michigan), has been awarded $200,000 through a new NSF grant to support the construction of a multiplexed array of plasmonically enhanced resonators, which should allow a variety of proteins to be identified in a blood serum within minutes.

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hivendra Panwar, professor of electrical and computer engineering, has developed a new technique called streamloading. The patent-pending technology is set to eliminate streaming problems,

such as buffering and spinning cursors, forever. While traditional streaming downloads 30 to 60 seconds of video ahead of time as video quality and speed vary based on wireless signal strength, stream-

SENSITIVITY TRAINING B IO-

Professor Stephen Arnold applies E N G I N E E R I N G breakthrough method to cancer detection

Just months after setting a record for detecting the smallest virus in solution, Professor Stephen Arnold and his researchers have announced another defining breakthrough. They detected a single cancer marker protein. The marker protein, which was one-sixth the size of the smallest virus, sets new limits on detection sensitivity. Their method, a nano-enhanced version of their

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microcavity biosensor, may improve early disease diagnostics. In 2012, Arnold and his team were able to detect in solution the smallest known RNA virus, MS2, with a mass of 6 attograms. Now, with experimental work by postdoctoral fellow Venkata Dantham and former student David Keng, two proteins have been

Cable Fall 2013 Issue  
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